When using an extraordinary assumption in a report, what must be included?

When employing an extraordinary assumption in an appraisal report, it is essential to state that its use may have affected the assignment results. This requirement emphasizes transparency and accountability in the appraisal process. By identifying the potential impact of the extraordinary assumption on the final results, the appraiser provides clarity regarding the reliability and validity of the conclusions drawn in the report.

Including this statement helps to inform the client and any third parties of the uncertainties in the appraisal process stemming from the extraordinary assumption. It reinforces that while the assumption may be necessary for the completion of the appraisal, it also introduces a level of risk concerning the accuracy of the valuation.

In contrast, other options pertain to aspects that are either not mandated or do not directly address the requirement of transparency regarding the influence of the extraordinary assumption on appraisal results. For instance, proof of client approval or providing a non-assumed value does not inherently convey the use's implications, while mentioning credibility could detract from the focus on the effects on the valuation process.